Because their screwed up political loyalties OUTWEIGHT any loyalty they have to their children.
Don't get vaccinated. So what? Who cares? Adults have that right.
But DON'T ALLOW YOUR CHILDREN TO BE PROTECTED? Do parents have the right to expose their children to death or harm just because they are owned body and soul by their political party?
I don't think so. Yet millions of them decide to not allow any vaccinations for their children. Loving parents or obedient partisan political sheeple? You decide.